edu.mines.jtk.interp

Class BicubicInterpolator2

java.lang.Object

edu.mines.jtk.interp.BicubicInterpolator2

public class BicubicInterpolator2
extends java.lang.Object

Piecewise bicubic polynomial interpolation of a function y(x1,x2). The interpolated function has continuous first derivatives dy/d1, dy/d2 and cross-derivatives ddy/d1d2. First derivatives are computed using methods that may be specified for each dimension. Cross-derivatives are computed by averaging derivatives of first derivatives.

The function y(x1,x2) is specified by samples on a regular grid, which need not be uniform. The regular grid is specified by one-dimensional arrays of monotonically increasing coordinates x1 and x2, such that gridded x1 are identical for all gridded x2, and gridded x2 are identical for all gridded x1.

Extrapolation (that is, interpolation outside the specified grid of (x1,x2) coordinates), is performed using cubic polynomials for the nearest grid samples. Extrapolated values can be well outside the [min,max] range of interpolated values, and should typically be avoided.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	BicubicInterpolator2.Method Method used to compute first derivatives.

Constructor Summary

Constructors

Constructor and Description
BicubicInterpolator2(BicubicInterpolator2.Method method1, BicubicInterpolator2.Method method2, float[] x1, float[] x2, float[][] y) Constructs an interpolator for specified methods and values.
BicubicInterpolator2(BicubicInterpolator2.Method method1, BicubicInterpolator2.Method method2, int n1, int n2, float[] x1, float[] x2, float[][] y) Constructs an interpolator for specified methods and values.
BicubicInterpolator2(float[] x1, float[] x2, float[][] y) Constructs an interpolator for specified values y(x1,x2).

Method Summary

Methods

Modifier and Type	Method and Description
float[][]	interpolate(float[] x1, float[] x2) Returns an array of interpolated values y.
void	interpolate(float[] x1, float[] x2, float[][] y) Computes an array of interpolated values y.
float	interpolate(float x1, float x2) Returns interpolated value y.
float[][]	interpolate(Sampling s1, Sampling s2) Returns an array of interpolated values y.
void	interpolate(Sampling s1, Sampling s2, float[][] y) Computes an array of interpolated values y.
float[][]	interpolate00(float[] x1, float[] x2) Returns an array of interpolated values y.
void	interpolate00(float[] x1, float[] x2, float[][] y) Computes an array of interpolated values y.
float	interpolate00(float x1, float x2) Returns interpolated value y.
float[][]	interpolate00(Sampling s1, Sampling s2) Returns an array of interpolated values y.
void	interpolate00(Sampling s1, Sampling s2, float[][] y) Computes an array of interpolated values y.
float	interpolate01(float x1, float x2) Returns interpolated partial derivative dy/d2.
float	interpolate10(float x1, float x2) Returns interpolated partial derivative dy/d1.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

BicubicInterpolator2

public BicubicInterpolator2(float[] x1,
                    float[] x2,
                    float[][] y)

Constructs an interpolator for specified values y(x1,x2).

Parameters:

x1 - array[n1] of x1 coordinates; monotonically increasing.

x2 - array[n2] of x2 coordinates; monotonically increasing.

y - array[n2][n1] of sampled values y(x1,x2).

BicubicInterpolator2

public BicubicInterpolator2(BicubicInterpolator2.Method method1,
                    BicubicInterpolator2.Method method2,
                    float[] x1,
                    float[] x2,
                    float[][] y)

Constructs an interpolator for specified methods and values.

Parameters:

method1 - method used to compute dy/d1.

method2 - method used to compute dy/d2.

x1 - array[n1] of x1 coordinates; monotonically increasing.

x2 - array[n2] of x2 coordinates; monotonically increasing.

y - array[n2][n1] of sampled values y(x1,x2).

BicubicInterpolator2

public BicubicInterpolator2(BicubicInterpolator2.Method method1,
                    BicubicInterpolator2.Method method2,
                    int n1,
                    int n2,
                    float[] x1,
                    float[] x2,
                    float[][] y)

Constructs an interpolator for specified methods and values.

Parameters:

method1 - method used to compute dy/d1.

method2 - method used to compute dy/d2.

n1 - number of x1 coordinates.

n2 - number of x2 coordinates.

x1 - array[n1] of x1 coordinates; monotonically increasing.

x2 - array[n2] of x2 coordinates; monotonically increasing.

y - array[n2][n1] of sampled values y(x1,x2).

Method Detail

interpolate

public float interpolate(float x1,
                float x2)

Returns interpolated value y. Same as interpolate00(float,float).

Parameters:

x1 - coordinate x1.

x2 - coordinate x2.

Returns:

interpolated y(x1,x2).

interpolate00

public float interpolate00(float x1,
                  float x2)

Returns interpolated value y.

Parameters:

x1 - coordinate x1.

x2 - coordinate x2.

Returns:

interpolated y(x1,x2).

interpolate10

public float interpolate10(float x1,
                  float x2)

Returns interpolated partial derivative dy/d1.

Parameters:

x1 - coordinate x1.

x2 - coordinate x2.

Returns:

interpolated dy/d1.

interpolate01

public float interpolate01(float x1,
                  float x2)

Returns interpolated partial derivative dy/d2.

Parameters:

x1 - coordinate x1.

x2 - coordinate x2.

Returns:

interpolated dy/d2.

interpolate

public float[][] interpolate(Sampling s1,
                    Sampling s2)

Returns an array of interpolated values y. Same as interpolate00(Sampling,Sampling).

Parameters:

s1 - sampling of coordinate x1.

s2 - sampling of coordinate x2.

Returns:

interpolated y(x1,x2).

interpolate00

public float[][] interpolate00(Sampling s1,
                      Sampling s2)

Returns an array of interpolated values y.

Parameters:

s1 - sampling of coordinate x1.

s2 - sampling of coordinate x2.

Returns:

interpolated y(x1,x2).

interpolate

public void interpolate(Sampling s1,
               Sampling s2,
               float[][] y)

Computes an array of interpolated values y. Same as interpolate00(Sampling,Sampling,float[][]).

Parameters:

s1 - sampling of coordinate x1.

s2 - sampling of coordinate x2.

y - output array of interpolated y(x1,x2).

interpolate00

public void interpolate00(Sampling s1,
                 Sampling s2,
                 float[][] y)

Computes an array of interpolated values y.

Parameters:

s1 - sampling of coordinate x1.

s2 - sampling of coordinate x2.

y - output array of interpolated y(x1,x2).

interpolate

public float[][] interpolate(float[] x1,
                    float[] x2)

Returns an array of interpolated values y. Same as interpolate00(float[],float[]).

Parameters:

x1 - array[n1] of coordinates x1.

x2 - array[n2] of coordinates x2.

Returns:

array[n2][n1] of interpolated y(x1,x2).

interpolate00

public float[][] interpolate00(float[] x1,
                      float[] x2)

Returns an array of interpolated values y.

Parameters:

x1 - array[n1] of coordinates x1.

x2 - array[n2] of coordinates x2.

Returns:

array[n2][n1] of interpolated y(x1,x2).

interpolate

public void interpolate(float[] x1,
               float[] x2,
               float[][] y)

Computes an array of interpolated values y. Same as interpolate00(float[],float[],float[][]).

Parameters:

x1 - array[n1] of coordinates x1.

x2 - array[n2] of coordinates x2.

y - output array[n2][n1] of interpolated y(x1,x2).

interpolate00

public void interpolate00(float[] x1,
                 float[] x2,
                 float[][] y)

Computes an array of interpolated values y.

Parameters:

x1 - array[n1] of coordinates x1.

x2 - array[n2] of coordinates x2.

y - output array[n2][n1] of interpolated y(x1,x2).